Last night's vice presidential debate offered a reminder about American politics. It can be infuriating, misleading and irrelevant, but at its best politics becomes a spectacle - a highly informative show - which is what the vice presidential candidates delivered last night in a debate in Kentucky.

It is hard to say if their spirited discussion changed any minds or won over undecided voters, but Republicans saw their candidate, Congressman Paul Ryan, contend solidly with his older opponent. Democrats found release in Biden's fierce correcting of the record - after President Obama's widely criticized showing last week.

NPR's Don Gonyea reports.

DON GONYEA, BYLINE: Debate moderator Martha Raddatz of ABC News started with the foreign policy issue of the day, Libya, and the attack last month that killed four Americans, including Ambassador Chris Stevens.

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MARTHA RADDATZ: The State Department has now made clear there were no protesters there. It was a pre-planned assault by heavily armed men. Wasn't this a massive intelligence failure, Vice President Biden?

GONYEA: Biden began his answer...

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VICE PRESIDENT JOE BIDEN: What it was, it was a tragedy, Martha. It - Chris Stevens was one of our best. We lost three other brave Americans.

GONYEA: But he quickly turned to a criticism of Governor Romney's foreign policy positions, signaling right away that he'd be much more aggressive than President Obama had been in last week's debate. Biden said the president has a strong record. He cited ending U.S. combat operations in Iraq and the killing of Osama bin Laden. He then pointed to a Mitt Romney line about bin Laden from years ago.

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BIDEN: Governor Romney was asked a question about how he would proceed. He said I wouldn't move heaven and earth to get bin Laden. He didn't understand it was more than about taking a - a murderer off the battlefield. It was about restoring America's heart and letting terrorists around the world know if you do harm to America, we will track you to the gates of hell, if need be. And lastly, the - the president of the United States has - has led with a steady hand and clear vision. Governor Romney, the opposite.

GONYEA: But Congressman Ryan followed by describing the events in Libya as, quote, "emblematic of a chaotic foreign policy."

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PAUL RYAN: It took the president two weeks to acknowledge that this was a terrorist attack. He went to the U.N., and in his speech at the U.N. he said six times - he talked about the YouTube video. Look, if we are hit by terrorists, we're going to call it for what it is, a terrorist attack. Our ambassador in Paris has a Marine detachment guarding him. Shouldn't we have a Marine detachment guarding our ambassador in Benghazi, a place where we knew that there was an al-Qaida cell with arms? This is becoming more troubling by the day.

GONYEA: Next, another thorny foreign policy issue, nuclear weapons and Iran. Ryan called it another failure by the president.

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RYAN: They're four years closer toward a nuclear weapons capability. We've had four different sanctions at the U.N. on Iran, three from the Bush administration, one here. And the only reason we got it is because Russia watered it down and prevented the sanctions from hitting the Central Bank. Mitt Romney proposed these sanctions in 2007. In Congress, I've been fighting for these sanctions since 2009. The administration was blocking us every step of the way.

GONYEA: Biden often reacted to Ryan's statements with disbelief and laughter - or with something like this...

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BIDEN: With all due respect, that's a bunch of malarkey.

GONYEA: On the economy, Biden said it was in freefall when the president took office. He called it the great recession. Ryan countered...

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RYAN: Joe and I are from similar towns. He's from Scranton, Pennsylvania. I'm from Janesville, Wisconsin. You know what the unemployment rate in Scranton is today?

BIDEN: I sure do.

RYAN: It's 10 percent.

BIDEN: Yeah.

RYAN: You know what it was the day you guys came in? Eight-point-five percent.

RYAN: Look. Did they come in and inherit a tough situation? Absolutely. But we're going in the wrong direction.

GONYEA: Throughout the 90 minutes, Raddatz kept a rein on the combatants, giving them time to argue, but also keeping them on topic. Ryan defended his running mate against Democratic charges that he would have done nothing to help the auto industry when General Motors and Chrysler were near death's door in 2008 and 2009. Biden and the president frequently quote a newspaper editorial Romney wrote back then with the headline "Let Detroit Go Bankrupt."

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RYAN: He talks about Detroit. Mitt Romney's a car guy. They keep misquoting him, but let me tell you about the Mitt Romney I know. This is a guy who I was talking to a family in Northborough, Massachusetts the other day - Cheryl and Mark Nixon. Their kids were hit in a car crash - four of them. Two of them, Rob and Reed, were paralyzed. The Romneys didn't know them. They went to the same church. They never met before.

GONYEA: Ryan went on to describe how Romney visited that family one Christmas.

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RYAN: Later on he said, I know you're struggling, Mark. Don't worry about their college - I'll pay for it. When Mark told me this story - because, you know what, Mitt Romney doesn't tell these stories.

GONYEA: Here's Biden.

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BIDEN: I don't doubt his personal commitment to individuals. But you know what, I know he had no commitment to the automobile industry. He just - he said let it go bankrupt, period. Let it drop out. All this talk - we saved a million jobs, 200,000 people are working today. And I've never met two guys who are more down on America across the board.

GONYEA: The exchanges were often heated. Each interrupted the other, though Biden was more aggressive on that score - a tactic widely predicted as a reaction to the president's low-key showing last week, prompting this from Ryan.

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RYAN: I know you're under a lot of duress to make up for lost ground, but I think people will be better served if we don't keep interrupting each other.

BIDEN: Well, don't take all the four minutes then.

GONYEA: And they battled over whether Romney can cut tax rates across the board by 20 percent, as promised, and find enough current tax deductions to eliminate that he doesn't have to raise the final tax result for the middle class or add to the deficit. Biden said it is impossible. Here's Ryan...

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RYAN: He is wrong about that. There...

BIDEN: How's that?

RYAN: You can cut tax rates by 20 percent and still preserve these important preferences for middle-class taxpayers...

BIDEN: Not mathematically possible.

RYAN: It is mathematically possible. It's been done before. It's what we're proposing.

GONYEA: The subject switched back to foreign policy and the wisdom of setting the firm timetable for pulling out of Afghanistan by 2014. There was agreement that the timetable is reasonable but by setting a hard date, Ryan said the administration helps the enemy. And he said it comes in the middle of a fighting season. He said that's a mistake.

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RYAN: Here's the way it works: the mountain passes fill in with snow, the Taliban and the terrorists and the Haqqani and the Quetta Shura come over from Pakistan to fight our men and women. When it fills in with snow, they can't do it. That's what we call fighting seasons. In the warm months, fighting gets really high. In the winter, it goes down. And so when Admiral Mullen and General Petraeus came to Congress and said if you pull these people out before the fighting season has ended, it puts people more at risk. That's the problem.

GONYEA: Here is Biden...

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BIDEN: We turned it over...

RYAN: But we pulled 22,000 people out...

BIDEN: ...we turned it over...

RYAN: ...for them to do it.

BIDEN: ...to the Afghan troops we trained. No one got pulled out that didn't get filled in by trained Afghan personnel. And he's conflating two issues. The fighting season that Petraeus was talking about and former - and Admiral Mullen - was the fighting season this spring. That's what he was talking about. We did not, we did not pull them out.

RYAN: The calendar works the same every year.

GONYEA: And that's how much of this debate felt. Historically, vice presidential debates have not had a measurable effect on the election result, but they often contribute to the dynamics along the way. That may hold true this year. Ryan has proven he can hold his own against a seasoned opponent and Biden has shown that counterpunching may be the incumbents' best strategy in the next debate next week. Don Gonyea, NPR News, Danville, Kentucky.

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